datadrivereh.pas

来自「EHLIB控件源码,很好用的表格控件,可进行统计求和功能.」· PAS 代码 · 共 1,855 行 · 第 1/5 页

        AssignFieldValue(MemRecord.DataStruct.MemTableData, MemRecord, i,
          dvvOldestValue, RecDataSet)
{      begin
        Field := RecDataSet.FindField(MemRecord.DataStruct[i].FieldName);
        if Field <> nil then
          MemRecord.Value[i, dvtOldestValue] := Field.Value;
      end;}

    finally
      if AFreeOnEof then
        RecDataSet.Free;
    end;
  end;
end;

function TCustomSQLDataDriverEh.DoUpdateRecord(MemTableData: TMemTableDataEh; MemRec: TMemoryRecordEh): Integer;
var
  Command: TCustomSQLCommandEh;
  ResDataSet: TDataSet;
  AFreeOnEof: Boolean;
begin
  Result := 0;
  if ResolveToDataSet then
    Result := inherited DefaultUpdateRecord(MemTableData, MemRec)
  else
  begin
    Command := nil;
    if  ((MemRec.UpdateStatus = usModified) and (dsoDynamicSQLUpdateEh in DynaSQLParams.Options))
     or ((MemRec.UpdateStatus = usInserted) and (dsoDynamicSQLInsertEh in DynaSQLParams.Options))
     or ((MemRec.UpdateStatus = usDeleted) and (dsoDynamicSQLDeleteEh in DynaSQLParams.Options)) then
    begin
      GenerateDynamicSQLCommand(MemRec, ServiceCommand);
      Command := ServiceCommand;
    end else
      case MemRec.UpdateStatus of
        usModified: Command := UpdateCommand;
        usInserted: Command := InsertCommand;
        usDeleted: Command := DeleteCommand;
      end;
    if Command = nil then Exit;
    Command.RefreshParams(MemRec, dvvValueEh);
    Result := ExecuteCommand(Command, ResDataSet, AFreeOnEof);
    GetBackUpdatedValues(MemRec, Command, ResDataSet);
    if AFreeOnEof then
      ResDataSet.Free;
//    MemRec.MergeChanges;
  end
end;

function TCustomSQLDataDriverEh.DefaultUpdateRecord(MemTableData: TMemTableDataEh;
  MemRec: TMemoryRecordEh): Integer;
var
  Processed: Boolean;
begin
  Result := 0;
  Processed := False;
  if Assigned(FDefaultSQLDataDriverResolver) then
    FDefaultSQLDataDriverResolver.UpdateRecord(Self, MemTableData, MemRec, Processed);
  if not Processed then
  begin
    if InternalGetServerSpecOperations <> nil
      then Result := InternalGetServerSpecOperations.UpdateRecord(Self, MemTableData, MemRec)
      else Result := DoUpdateRecord(MemTableData, MemRec);
  end;
end;

procedure TCustomSQLDataDriverEh.GetBackUpdatedValues(MemRec: TMemoryRecordEh; Command: TCustomSQLCommandEh; ResDataSet: TDataSet);
begin
  if Assigned(FOnGetBackUpdatedValues)
    then OnGetBackUpdatedValues(Self, MemRec, Command, ResDataSet)
    else DefaultGetUpdatedServerValues(MemRec, Command, ResDataSet);
end;

procedure TCustomSQLDataDriverEh.DefaultGetUpdatedServerValues(
  MemRec: TMemoryRecordEh; Command: TCustomSQLCommandEh; ResDataSet: TDataSet);
var
  Processed: Boolean;
begin
  Processed := False;
  if Assigned(FDefaultSQLDataDriverResolver) then
    FDefaultSQLDataDriverResolver.GetBackUpdatedValues(Self, MemRec, Command, ResDataSet, Processed);
  if not Processed and (InternalGetServerSpecOperations <> nil) then
    InternalGetServerSpecOperations.GetBackUpdatedValues(MemRec, Command, ResDataSet);
end;

function TCustomSQLDataDriverEh.CreateDeleteCommand: TCustomSQLCommandEh;
begin
  Result := CreateCommand;
end;

function TCustomSQLDataDriverEh.CreateInsertCommand: TCustomSQLCommandEh;
begin
  Result := CreateCommand;
end;

function TCustomSQLDataDriverEh.CreateSelectCommand: TCustomSQLCommandEh;
begin
  Result := CreateCommand;
end;

function TCustomSQLDataDriverEh.CreateGetrecCommand: TCustomSQLCommandEh;
begin
  Result := CreateCommand;
end;

function TCustomSQLDataDriverEh.CreateUpdateCommand: TCustomSQLCommandEh;
begin
  Result := CreateCommand;
end;

{
function TCustomSQLDataDriverEh.GetReaderDataSet: TDataSet;
begin
  if ProviderDataSet <> nil
    then Result := inherited GetReaderDataSet
    else Result := FReaderDataSet;
end;
}

function TCustomSQLDataDriverEh.GetDefaultCommandTypeFor(Command: TCustomSQLCommandEh): TSQLCommandTypeEh;
begin
  if (Command = SelectCommand) or (Command = GetrecCommand)
    then Result := cthSelectQuery
    else Result := cthUpdateQuery;
end;

procedure RegisterDesignDataBuilderProcEh(DataDriverClass: TSQLDataDriverEhClass;
  DesignDataBaseProc: TSetDesignDataBaseProcEh);
var
  ExistsIdx: Integer;
begin
  if DesignDataBuilderClasses = nil then
  begin
    DesignDataBuilderClasses := TList.Create;
    DesignDataBuilderProcs := TList.Create;
  end;
  ExistsIdx := DesignDataBuilderClasses.IndexOf(TObject(DataDriverClass));
  if ExistsIdx >= 0 then
    DesignDataBuilderProcs[ExistsIdx] := @DesignDataBaseProc
  else
  begin
    DesignDataBuilderClasses.Add(TObject(DataDriverClass));
    DesignDataBuilderProcs.Add(@DesignDataBaseProc);
  end;
end;

procedure UnregisterDesignDataBuilderProcEh(DataDriverClass: TSQLDataDriverEhClass);
var
  ExistsIdx: Integer;
begin
  if DesignDataBuilderClasses = nil then Exit;
  ExistsIdx := DesignDataBuilderClasses.IndexOf(TObject(DataDriverClass));
  if ExistsIdx >= 0 then
  begin
    DesignDataBuilderClasses.Delete(ExistsIdx);
    DesignDataBuilderProcs.Delete(ExistsIdx);
  end;
end;

function GetDesignDataBuilderProcEh(DataDriverClass: TSQLDataDriverEhClass):
  TSetDesignDataBaseProcEh;

  function GetDatasetFeaturesDeep(ARootClass, AClass: TClass): Integer;
  begin
    Result := 0;
    while True do
    begin
      if ARootClass = AClass then
        Exit;
      Inc(Result);
      AClass := AClass.ClassParent;
      if AClass = nil then
      begin
        Result := MAXINT;
        Exit;
      end;
    end;
  end;

var
  Deep, MeenDeep, i: Integer;
  TargetClass: TSQLDataDriverEhClass;
begin
  Result := nil;
  if DesignDataBuilderClasses = nil then Exit;
  MeenDeep := MAXINT;
  for i := 0 to DesignDataBuilderClasses.Count - 1 do
  begin
    if DataDriverClass.InheritsFrom(TSQLDataDriverEhClass(DesignDataBuilderClasses[i])) then
    begin
      TargetClass := TSQLDataDriverEhClass(DesignDataBuilderClasses[i]);
      Deep := GetDatasetFeaturesDeep(TargetClass, DataDriverClass);
      if Deep < MeenDeep then
      begin
        MeenDeep := Deep;
        Result := TSetDesignDataBaseProcEh(DesignDataBuilderProcs[i]);
      end;
    end;
  end;
end;

function TCustomSQLDataDriverEh.CreateDesignDataBase: TComponent;
begin
  Result := nil;
end;

procedure TCustomSQLDataDriverEh.AssignFromDesignDriver(DesignDataDriver: TCustomSQLDataDriverEh);
begin
  SelectCommand := DesignDataDriver.SelectCommand;
  UpdateCommand := DesignDataDriver.UpdateCommand;
  InsertCommand := DesignDataDriver.InsertCommand;
  DeleteCommand := DesignDataDriver.DeleteCommand;
  GetrecCommand := DesignDataDriver.GetrecCommand;
end;

function TCustomSQLDataDriverEh.CreateDesignCopy: TCustomSQLDataDriverEh;
begin
  Result := TCustomSQLDataDriverEh.Create(nil);
  Result.SelectCommand := SelectCommand;
  Result.UpdateCommand := UpdateCommand;
  Result.InsertCommand := InsertCommand;
  Result.DeleteCommand := DeleteCommand;
  Result.GetrecCommand := GetrecCommand;
end;


function TCustomSQLDataDriverEh.GetSelectSQL: TStrings;
begin
  Result := SelectCommand.CommandText;
end;

procedure TCustomSQLDataDriverEh.SetSelectSQL(const Value: TStrings);
begin
  SelectCommand.CommandText := Value;
end;

function TCustomSQLDataDriverEh.GetDeleteSQL: TStrings;
begin
  Result := DeleteCommand.CommandText;
end;

procedure TCustomSQLDataDriverEh.SetDeleteSQL(const Value: TStrings);
begin
  DeleteCommand.CommandText := Value;
end;

function TCustomSQLDataDriverEh.GetGetrecSQL: TStrings;
begin
  Result := GetrecCommand.CommandText;
end;

procedure TCustomSQLDataDriverEh.SetGetrecSQL(const Value: TStrings);
begin
  GetrecCommand.CommandText := Value;
end;

function TCustomSQLDataDriverEh.GetInsertSQL: TStrings;
begin
  Result := InsertCommand.CommandText;
end;

procedure TCustomSQLDataDriverEh.SetInsertSQL(const Value: TStrings);
begin
  InsertCommand.CommandText := Value;
end;

function TCustomSQLDataDriverEh.GetUpdateSQL: TStrings;
begin
  Result := UpdateCommand.CommandText;
end;

procedure TCustomSQLDataDriverEh.SetUpdateSQL(const Value: TStrings);
begin
  UpdateCommand.CommandText := Value;
end;

function TCustomSQLDataDriverEh.GetDesignDataBase: TComponent;
var
  SetBaseProc: TSetDesignDataBaseProcEh;
begin
  Result := nil;
  SetBaseProc := GetDesignDataBuilderProcEh(TSQLDataDriverEhClass(ClassType));
  if @SetBaseProc = nil then Exit;
  SetBaseProc(Self);
  Result := FDesignDataBase;
end;

procedure TCustomSQLDataDriverEh.SetDesignDataBase(const Value: TComponent);
begin
  if FDesignDataBase <> Value then
  begin
    FDesignDataBase := Value;
    if Value <> nil then Value.FreeNotification(Self);
  end;
end;

procedure TCustomSQLDataDriverEh.Notification(AComponent: TComponent; Operation: TOperation);
begin
  inherited Notification(AComponent, Operation);
  if (Operation = opRemove) and
     (AComponent <> nil) and
     (FDesignDataBase = AComponent)
  then
    FDesignDataBase := nil;
end;

function TCustomSQLDataDriverEh.RefreshReaderParamsFromCursor(DataSet: TDataSet): Boolean;
var
  FParams: TParams;
  Field: TField;
  I: Integer;
begin
  if (ProviderDataSet <> nil) then
    Result := inherited RefreshReaderParamsFromCursor(DataSet)
  else
  begin
    Result := False;
    FParams := SelectCommand.GetParams;
    if FParams <> nil then
      for I := 0 to FParams.Count - 1 do
      begin
        Field := DataSet.FindField(FParams[I].Name);
        if (Field <> nil) and not VarEquals(Field.Value, FParams[I].Value) then
        begin
          Result := True;
          Break;
        end;
      end;
  end;
end;

procedure TCustomSQLDataDriverEh.SetReaderParamsFromCursor(DataSet: TDataSet);
var
  I: Integer;
  FParams: TParams;
begin
  if (ProviderDataSet <> nil) then
    inherited SetReaderParamsFromCursor(DataSet)
  else
  begin
    FParams := SelectCommand.GetParams;
    if FParams <> nil then
    begin
      DataSet.FieldDefs.Update;
      for I := 0 to FParams.Count - 1 do
        with FParams[I] do
        begin
//          if not Bound then
//          begin
            AssignField(DataSet.FieldByName(Name));
            Bound := False;
//          end;
        end;
    end;
    SelectCommand.SetParams(FParams);
  end;
end;

procedure TCustomSQLDataDriverEh.SetSpecParams(const Value: TStrings);
begin
  FSpecParams.Assign(Value);
end;

function TCustomSQLDataDriverEh.HaveDataConnection: Boolean;
begin
  Result := False;
end;

function TCustomSQLDataDriverEh.CreateCommand: TCustomSQLCommandEh;
begin
  Result := TCustomSQLComman